35
en
Switch-on temperature difference
∆
Ton too large?
Non-ideal position of the collector
sensor (e. g. flatscrew sensor
instead of sensor in immersion
sleeves).
The temperature difference between store and collector increases enormous-
ly during operation; the collector circuit cannot dissipate the heat
Collector circuit pump defective?
Heat exchanger calcified?
Heat exchanger blocked?
Heat exchanger too small?
The fuse of the controller could
be blown. The fuse holder (which
holds the spare fuse) becomes ac-
cessible when the cover is removed.
The fuse can then be replaced.
Pump is overheated, but no heat transfer from the collector to the store, flow
and return have the same temperature; perhaps also bubbling in the lines.
Air or gas bubbles in the system?
Is the collector circuit blocked at
the dirt trap?
Pump starts for a short moment, switches off, switches on again, etc.
Temperature difference at the
controller too small?
Wrong position of collector
sensors?
Plausibility control of the option
tube collector special function
Operating control LED is permanently off
If the operating control LED is off, check the power supply of the controller. Is
it disconnected?
Vent the system; increase the
system pressure to a static primary
pressure of at least plus 0.5 bar;
if necessary continue to increase
pressure; switch the pump on and
off for a short time.
no
no
no
no
no
no
no
no
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
Clean dirt trap
Check the supply line and recon-
nect it.
Change
∆
Ton and
∆
Toff corre-
spondingly.
Mount the collector sensor at
solar flow (warmest collector
output); use immersion sleeve of
the respective collector.
no
o.k.
Pump starts up very late.
Change
∆
Ton and
∆
Toff corre-
spondingly.
Activate tube collector function if
necessary.
o.k.
Check / replace it
Decalcify it
Clean it
Replace with correctly sized one.
